Description Acanthurus coeruleus (also known as the Atlantic blue tang surgeonfish or the Atlantic blue tang) is a surgeonfish found commonly in the Atlantic Ocean.

Although the body of the reef fish can vary in shade from light to dark blue, the dorsal, anal and caudal fins are golden blue. As juveniles, the edges on their dorsal and anal fins and the rings around their eyes are purple-blue, blue or blue-green. Juveniles may also be larger than adults and are called Atlantic yellow tang surgeonfish until they become adults. Their colors change during growth from a yellow juvenile, yellow tailed blue subadult and the blue adult phase.

Warning Members of this family have a sharp, scalpel-like spine and should be handled with care. The flesh of the Blue Tang is toxic if eaten.